ABSTRACT
Benjamin Franklin proved an important scientifi c point, which is that electricity originates inside clouds. There, it forms into lightning, which is attracted to the earth by golfers. After entering the ground, the electricity hardens into coal, which, when dug up by power companies and burned in big ovens called “generators,” turns back into electricity, which is sent in the form of “volts” (also known as “watts,” or “rpm” for short), through special wires with birds sitting on them to consumers’ homes, where it is transformed by TV sets into commercials for beer, which passes through the consumers and back into the ground, thus completing what is known as a “circuit.”—Dave Barry
One of the keys to understanding automated lighting, or any lighting, for that matter, is to follow the fl ow of energy from the input to the output. A fundamental law of nature is that energy can be neither created nor destroyed; it can only change forms. Electricity is one form of energy, and the job of any lighting system is to take electrical energy and effi ciently convert it to light energy. In the real world, only a fraction of the energy put into a lighting system comes out as visible light. Most is lost to heat, some is lost to mechanical energy, and some is converted to invisible light waves.
